Production method for solid image pickup device

ABSTRACT

The production method provides a method of producing a solid image pickup device. The solid image pickup device comprises a solid image pickup element, and an optical lens held in a housing provided in a flexible wiring board. The fixing device bonds and fixes the flexible wiring board in a folded state corresponding to an external shape of the solid image pickup device.

FIELD OF THE INVENTION

[0001] The present invention relates to a production method for a solid image pickup device comprising a solid image pickup element and an optical lens. More specifically, this invention relates to a production method for a solid image pickup device suitable for the miniaturization of the device, having a small volume and a high performance external shape size accuracy.

BACKGROUND OF THE INVENTION

[0002]FIG. 13 shows an example of a conventional production method for a solid image pickup device. The solid image pickup device comprises a solid image pickup element and an optical lens, with a flexible wiring board folded and fixed. In FIG. 13, the numeral 1 denotes a flexible wiring board (hereinafter referred to as an FPC), 1 a an FPC lead section, 2 a reinforcing plate, 3 an external connection element, 4 a fixed base, 5 a fixed cap, 13 a housing, and 101 a pressing clip, respectively.

[0003] The conventional production method will be explained while referring to FIG. 13. First, the FPC 1 is folded for the miniaturization of the device. An adhesive is applied or filled in the inner part of the folded FPC 1 generated at the time. Then, it is clipped by the pressing clip 101 such that the fixed cap 5 and the FPC 1 are forced lightly by the spring force of the pressing clip 101. Next, by hardening the adhesive in this state, a miniaturized solid image pickup device can be obtained.

[0004] Since the conventional solid image pickup device has the above-mentioned configuration, it is difficult to stabilize the spring force of the pressing clip 101 at the time of folding the FPC 1 and fixing the same with the adhesive so as to give rise to the problem of a large external size irregularity.

[0005] Moreover, since irregularity is generated in terms of the spring force of the pressing clip 101 and the position of the load applied on the contacting part at the time of clipping, a problem of difficulty in constantly providing the solid image pickup device shape, is involved.

[0006] Since the shape instability and the external size irregularity give rise to the need of having an excessive size tolerance in a storage space in storing the solid image pickup device in a case or the like, it involves a serious problem in designing in the case of, in particular, mounting in a small appliance such as a portable phone. Furthermore, the part of the fixed cap 5 to be contacted with the pressing clip 101 can easily be flawed, and thus a problem is also involved in terms of the external appearance.

SUMMARY OF THE INVENTION

[0007] It is an object of this invention to provide a solid image pickup device with a miniaturized shape and size, and a reduced size error while maintaining the image pickup performance and the shape performance of the solid image pickup device so as to enable easily assembly in a small appliance, such as a portable phone.

[0008] The production method according to one aspect of this invention provides a method of producing a solid image pickup device comprising a solid image pickup element, and an optical lens held in a housing provided in a flexible wiring board. This method comprises, using a fixing device, bonding and fixing the flexible wiring board in a folded state corresponding to an external shape of the solid image pickup device. According to this method, the part in contact with the fixed cap and the part in contact with the flexible wiring board (or the reinforcing plate) can always be pressured at the same position.

[0009] The production method according to another aspect of this invention provides a method of producing a solid image pickup device comprising a solid image pickup element, an optical lens held in a housing, and an IC part provided in a flexible wiring board. This method comprises, using a fixing device, bonding and fixing the flexible wiring board in a folded state corresponding to an external shape of the solid image pickup device.

[0010] Other objects and features of this invention will become apparent from the following description with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a developed view of an FPC according to a first embodiment of the present invention,

[0012]FIG. 2 is a developed view of the FPC according to the first embodiment of the present invention,

[0013]FIG. 3 is a developed view of the FPC according to the first embodiment of the present invention,

[0014]FIG. 4 is across-sectional view of a solid image pickup device according to the first embodiment of the present invention,

[0015]FIG. 5 is a developed view of the FPC according to the first embodiment of the present invention,

[0016]FIG. 6 is a cross-sectional view of the solid image pickup device according to the first embodiment of the present invention,

[0017]FIG. 7 is a diagram showing the external appearance of a pressing section of a fixing device according to the first embodiment of the present invention,

[0018]FIG. 8 is a diagram showing the external appearance of a holding section of the fixing device according to the first embodiment of the present invention,

[0019]FIG. 9 is a diagram showing the external appearance of the positional relationship between the fixing device and the solid image pickup device according to the first embodiment of the present invention,

[0020]FIG. 10 is a cross-sectional view of the configuration at the time of bonding according to the first embodiment of the present invention,

[0021]FIG. 11 is a diagram showing the external appearance of the solid image pickup device according to the first embodiment of the present invention,

[0022]FIG. 12 is a cross-sectional view of the solid image pickup device according to the first embodiment of the present invention, and

[0023]FIG. 13 is a diagram showing the external appearance of a conventional production method for a solid image pickup device.

DETAILED DESCRIPTIONS

[0024] Embodiments of the present invention will be explained below while referring to the accompanying drawings.

[0025] FIGS. 1 to 6 are show the structure and the production procedure of a solid image pickup device according to first embodiment of the present invention.

[0026]FIG. 1 shows the shape of the FPC 1 comprising a film material made of a polyimide, or the like. The broken line parts show the positions to be folded. Moreover, the numeral 1 a denotes an FPC lead line section, and the numeral 3 an external connection terminal, which represent a part of the FPC 1.

[0027]FIG. 2 shows the state with a reinforcing plate 2 a and a reinforcing plate 2 b attached on the FPC 1. The reinforcing plate 2 b is provided with an opening section 14 for focusing an image by directing a light beam to an image pickup area of a solid image pickup element 9. Moreover, the frame of the broken line under the reinforcing plate 2 a denotes the mounting position for an IC part 10, and the frame of the broken line under the reinforcing plate 2 b denotes the mounting position for the solid image pickup element 9, respectively.

[0028]FIG. 3 shows the state with a chip part 12 mounted on the FPC 1 by soldering, and the solid image pickup device 9 and the IC part 10 mounted by the flip chip bonding.

[0029]FIG. 4 is a cross-sectional view in the state with the optical parts mounted. The numeral 4 denotes a fixed base, 5 a fixed cap, 6 an optical lens, 7 an optical filter, and 8 a diaphragm section, respectively. The numeral 11 denotes a flip chip connection section.

[0030]FIG. 5 shows the state with an adhesive 15 provided on the FPC 1. Here, the adhesive 15 may be a liquid adhesive coated and dried, or a sheet-like adhesive attached. FIG. 5 shows the state with a sheet-like adhesive film attached on the solid image pickup element 9 and the chip part 12. Moreover, FIG. 6 is a cross-sectional view of FIG. 5.

[0031]FIGS. 7 and 8 show a fixing device used in the production method according to the present invention. FIG. 7 shows a pressing section 102, and FIG. 8 shows a holding section 103. Moreover, a projection part of the pressing section 102 is fitted with a corresponding recess part of the holding section 103. Here, the solid image pickup device is folded at the broken line part of the FPC 1 so as to be placed on the recess part provided in the holding section 103 in the folded state. The recess part shape is provided so as to match the outer shape of the folded solid image pickup device. Then, the pressing section 103 is fitted into the holding section 103 by a certain pressure so as to be fixed. After hardening the adhesive 15 so as to complete the adhesion and fixation, a miniaturized solid image pickup device 201 can be taken out from the fixing device and obtained.

[0032] The positional relationship of the above-mentioned fixing device and the solid image pickup device 201 is shown further in FIG. 9.

[0033] Here, the adhesive 15 may be hardened in an ordinary temperature, or hardened by heating in a heating furnace together with the fixing device.

[0034] Moreover, the certain pressure applied on the pressing section 102 may be provided by placing a weight of a certain load on the pressing section 102, or by providing a screw hole in the holding section 103 and fastening the pressing section 102 with a bolt, or the like.

[0035]FIG. 10 is a cross-sectional view showing the state with the solid image pickup device 201 fitted in the pressing section 102 and the holding section 103.

[0036] Moreover, FIG. 11 shows the external appearance of the solid image pickup device 201 according to a production method of the present invention, completed by taking out from the fixing device, and evening the external shape.

[0037] Furthermore, FIG. 12 is a cross-sectional view of the principal part of the solid image pickup device 201 shown in FIG. 11.

[0038] Since the solid image pickup device according to the first embodiment of the present invention is produced in the above-mentioned configuration, the part of the pressing section 102 in contact with the fixed cap 5 and the part of the holding section 103 in contact with the FPC 1 (or the reinforcing plate 2 a) can be pressured always at the same position as well as the contacted part of the side surface part of the solid image pickup device can further be at the same position, the pressing force can be stabilized on the entire surface of the solid image pickup device so that the shape of the produced solid image pickup device can be constant and even and irregularity of the external size value can be reduced at a low level.

[0039] As a second embodiment of this invention, a degassing hole may be provided in the pressing section 102 and the holding section 103 with the other configuration being the same as the fixing device explained in the first embodiment. This will facilitate the discharge of the gas generated from the adhesive 15 to the outside at the time of bonding and fixing. If the adhesive 15 is such that it does not generate a gas, then the degassing hole need not be provided.

[0040] As heretofore explained, the production method for a solid image pickup device according to the present invention comprises bonding and fixing a folded flexible wiring board with an adhesive after being fitted in a mold corresponding to the external shape of the solid image pickup device, and taking out from the mold after completing the bonding and fixation by hardening the adhesive. Therefore, the part in contact with the fixed cap and the part in contact with the flexible wiring board (or the reinforcing plate) can always be pressured at the same position, and thus the shape of the produced solid image pickup device can be constant and even and irregularity of the external size value can be reduced at a low level.

[0041] Moreover, the contacted part are always pressed at the same position also as to the side surface part of the solid image pickup device so that the pressing force can be stabilized on the entire surface of the solid image pickup device. Therefore, the shape of the produced solid image pickup device can be stable and even and irregularity of the external size value can be reduced at a low level.

[0042] Furthermore, the solid image pickup element is provided on one surface and the optical lens on the other surface of the flexible wiring board. Therefore, a miniaturized solid image pickup device can be obtained.

[0043] Moreover, the flexible wiring board and the solid image pickup element are bonded, and further the flexible wiring board and an IC part by the flip chip connection. Therefore, a miniaturized solid image pickup device can be obtained.

[0044] Furthermore, a hole for ventilation is provided in a pressing section and a holding section for discharging the gas generated at the time of hardening an adhesive. Therefore, a bonding operation can be facilitated.

[0045] Moreover, the pressing section evenly pressures at the time of bonding. Therefore, a solid image pickup device with the excellent size accuracy can be obtained.

[0046] Furthermore, since the pressing section evenly pressures at the time of bonding, flaw, or the like can hardly be generated, and thus a solid image pickup device with a good external appearance can be obtained.

[0047] Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth. 

What is claimed is:
 1. A production method for a solid image pickup device, said solid image pickup device having a solid image pickup element, and an optical lens held in a housing provided in a flexible wiring board, the method comprising: using a fixing device, bonding and fixing said flexible wiring board in a folded state corresponding to an external shape of said solid image pickup device.
 2. The production method according to claim 1, comprising providing said solid image pickup element on one surface and providing said optical lens on other surface of said flexible wiring board.
 3. The production method according to claim 1, comprising integrating said flexible wiring board with a lead line and providing an electrode for the external connection on said lead line.
 4. The production method according to claim 1, comprising bonding said flexible wiring board and said solid image pickup element by a flip chip connection.
 5. The production method according to claim 1, wherein said housing holds an optical filter together with said optical lens.
 6. The production method according to claim 1, wherein said fixing device comprises at least a holding section for said solid image pickup device, and a pressing section for the time of bonding and fixing.
 7. The production method according to claim 6, wherein a degassing hole is provided in said pressing section of said fixing device.
 8. The production method according to claim 6, wherein a degassing hole is provided in the holding section for said image pickup device of said fixing device.
 9. A production method for a solid image pickup device, said solid image pickup device having a solid image pickup element, an optical lens held in a housing, and an IC part provided in a flexible wiring board, the method comprising: using a fixing device, bonding and fixing said flexible wiring board in a folded state corresponding to an external shape of said solid image pickup device.
 10. The production method according to claim 9, comprising bonding said flexible wiring board and said IC part by a flip chip connection.
 11. The production method according to claim 9, comprising bonding and fixing said solid image pickup element and said IC part.
 12. The production method according to claim 9, wherein said fixing device comprises at least a holding section for said solid image pickup device, and a pressing section for the time of bonding and fixing.
 13. The production method according to claim 12, wherein a degassing hole is provided in said pressing section of said fixing device.
 14. The production method according to claim 12, wherein a degassing hole is provided in the holding section for said image pickup device of said fixing device. 